The present invention relates to a storage device and particularly to a technique effectively applied to a load distribution with respect to a logical volume.
In recent years, in the current of a storage consolidation by a web server, and a content delivery, etc. a storage device is shared by a plurality of applications and contents, and there is increased a system in which a load condition of the storage device with respect to a logical volume cannot be expected by the respective applications.
Accordingly, in order to expand performance of the storage device with respect to a load of the logical volume, there have conventionally been a structure in which the same logical volume of data is divided into and relocated at a plurality of magnetic dick drive groups (see, for example, Japanese Patent Laid-open No. 9-69031), and a structure in which the divided data is further divided into and relocated at array groups defined by a sub system (see, for example, Japanese Patent Laid-open No. 2000-242439).